I was trying to get at, for you, why do you have a preference for the system(s) you do? Several of you have done this, and I thank you for that.
Thing is, I don't have a very consistent game-style. What I want out of the game changes from campaign to campaign. Since the goals vary so much, I find it hard to generalize.
For example, for your typical fantasy, I tend to use D&D. I prefer 3e because it has a goodly number of fiddly bits, to support a lot of detail in long-term campaign play.
But, when I'm running a supers game, I tend to like a game that is more rules-light, and I usually go with old FASERIP Marvel Superheros.
So, I can't say I like specifically rules-light, or rules-heavy. It depends on what I want at the time. Same goes for many other aspects of play.